The term also applies to ships where a small living crew stays awake while the rest (...the majority of those aboard) stay in suspended animation. Most examples of Sleeper Ships with FTL propulsion use this arrangement. [1]

There are tales of nanotech approaches that stock a ship with seeds and machines in order to build a civilization at the destination. If there actually were any ships like this, they would technically not be Sleeper Ships, as there would be nobody sleeping on the ship, but most of the details would be otherwise identical. [2]

Generation Ships are sometimes referred to, incorrectly, as Sleeper Ships, which are similar, except that the majority or all of the passengers and crew are put into low berth hibernation for the duration of the journey. [3]

In cases where a small portion of those aboard are awake, it is often common to be awake in shifts. For instance, the complement might include 5 crews, each of which handles 1/5th of the voyage then wakes up the next crew before sleeping out the rest of the trip. If the voyage takes 40 years, the crews will only have aged 8 years each, and remain available to participate in the new colony's early years. This also provides backup capability if something goes wrong, similar to the Frozen Watch but on a longer time scale. [4]

There are also cases where the voyage will only take a few years (sometimes a few weeks), and while the colonists may have skills useful at the colony most of them are not useful aboard ship. The colonists hibernate to reduce life support costs, and to facilitate use of smaller ships, while the crew remains awake for the entire voyage. In these cases, the crew - who are adjusted to shipboard life among the stars, and thus might make poor colonists - may continue flying the ship (possibly returning to where the colonists came from) after their cargo is delivered. [5]

This is sometimes used to build a colony up in stages with smaller ships. As an extreme example, a ship might carry only 1,000 colonists and their equipment at a time, to a colony 1 week-long jump away from the colonists' origin, building up to 1,000,000 colonists over 100 back-and-forth trips over the span of 40-50 years (2,000 weeks, plus time to load and unload 1,000 times each). These same ships are typically capable of much longer journeys; only the logistics of scheduling multiple trips in a reasonable time span limits their range for such operations. [6]